Improving thermoplastics - Compounders' role

The intrinsic properties of thermoplastic compounds, such as their low density and ease of processing, which allows the most complex shapes to be created at surprisingly high production rates, have enabled them to overwhelm our societies with elaborate, elegant, multifunctional and inexpensive objects.

In this article, we take a look at their composition, properties, manufacture and impact on our civilization.

Given the number of products used in the composition of thermoplastic compounds (figure A), and the flexibility of dosing each of them, it's easy to imagine the infinite possibilities. Faced with a rather vague request or a precise specification, the formulator will have to come up with the least costly and most suitable composition. In this article, we'll try to explain how a product is created, without going into too much detail that would make it confusing and incomprehensible.

In short, formulators or compounders work in a complementary market neglected by the big chemical companies, which produce virgin polymers in gigantic quantities. It's a job that's essential to enriching the range of materials available to designers of new plastic applications. It's up to them to imagine, develop and supply thermoplastics adapted to a specific part or assembly, using polymers, reinforcements and fillers, modifiers, additives, pigments, etc., available on the market. He or she will be confronted with both customer specifications and those of major official bodies such as Underwriters' Laboratories (UL), VDE (Association for Electrical, Electronic and Information Technologies), BSI (British Standards Institute); he or she will have to comply with ISO quality and environmental protection standards, and so on.

We will describe the basic materials, then the properties of a number of compositions. Finally, we will look at some special applications, such as flame-retardant and lubricated products, as well as some aspects of conductive thermoplastics. The influence of additives such as stabilizers, pigments, lubricants, etc. will also be discussed. We will then briefly describe manufacturing processes.